Device with assembly mechanism and electric pump

ABSTRACT

A device with an assembly mechanism may be provided. The device with the assembly mechanism may include: a first member; a second member; and a fastener fastening the first member and the second member to each other. The fastener may include a fastening portion being fastened to each of the first member and second member by injection welding; and the assembly mechanism that is integrally formed with the fastening portion, and is configured to assemble the device to an external device.

TECHNICAL FIELD

The present disclosure relates to a device with an assembly mechanism for attaching the device to an external device, and an electric pump to be attached to a vehicle body.

BACKGROUND

When a device is attached to an external device, an assembly mechanism is disposed at the device for attaching the device to the external device. For example, Japanese Patent Application Publication No. 2001-304200 describes a bracket for attaching a pump to a vehicle body. When the pump is to be attached to the vehicle body, the bracket is attached to the pump, and then the pump is attached to the vehicle body via the bracket.

SUMMARY

In the above technology, the bracket as an assembly mechanism needs to be prepared separately from the pump, and needs to be attached to the pump for attaching the pump to the vehicle body which is an external device.

The present disclosure provides a technology for doing away with a necessity to dispose as assembly mechanism separately from a device.

A device with an assembly mechanism disclosed herein may comprise: a first member; a second member; and a faster fastening the first member and the second member to each other. The fastener may comprise: a fastening portion being fastened to each of the first member and second member by injection welding; and the assembly mechanism that is integrally formed with the fastening portion, and is configured to assemble the device to an external device.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 shows a schematic cross-sectional view of an electric pump of a first embodiment.

FIG. 2 shows a plan view of the electric pump of the first embodiment.

FIG. 3 is a flow chart showing a method of forming a flange of the first embodiment.

FIG. 4 shows a schematic cross-sectional view of an electric pump of a second embodiment.

FIG. 5 shows a schematic cross-sectional view of an electric pump of a third embodiment.

FIG. 6 shows a plan view of an electric pump of a fourth embodiment.

FIG. 7 shows a plan view of an electric pump of a fifth embodiment.

FIG. 8 shows a cross-sectional view of an end face of an electric pump of a variant.

FIG. 9 shows a schematic cross-sectional view of a device with an assembly mechanism of a variant.

BRIEF DESCRIPTION

Representative, non-limiting examples of the present invention will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed below may be utilized separately or in conjunction with other features and teachings to provide improved device with assembly mechanism and electric pump, as well as methods for using and manufacturing the same.

Moreover, combinations of features and steps disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described and below-described representative examples, as well as the various independent and dependent claims, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

All features disclosed is the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the composition of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

A device with an assembly mechanism disclosed herein may comprise: a first member; a second member; and a fastener fastening the first member and the second member to each other. The fastener may comprise: a fastening portion being fastened to each of the first member and second member by injection welding; and the assembly mechanism that is integrally formed with the fastening portion, and is configured to assemble the device to an external device.

In the above configuration, the fastening portion fastening the first member and the second member to each other is integrally formed with the assembly mechanism for assembling the device with the assembly mechanism to the external device. Due to this, it is not necessary to prepare the assembly mechanism separately and to dispose the same in the device thereafter.

The first member may comprise a first opposing portion, and the second member may comprise a second opposing portion opposing the first opposing portion. The fastener may further comprise a first contacting portion contacting the first opposing portion at a side of the first opposing portion opposite from the second opposing portion. According to this configuration, the first member may be suppressed from moving away from the second member by the first contacting portion contacting the first opposing portion.

The first member may further comprise a first holding portion disposed at a side of the first contacting portion opposite from the first opposing portion. The first contacting portion may be interposed between the first opposing portion and the first holding portion. According to this configuration, the first member and the fastener may be firmly fixed by interposing the fastener between the first opposing portion and the first holding portion of the first member.

The fastener may further comprise a second contacting portion contacting the second opposing portion at a side of the second opposing portion opposite from the first opposing portion. According to this configuration, the first opposing portion and the second opposing portion may be interposed between the first contacting portion and the second contacting portion. Due to this, the first opposing portion and the second opposing portion may be suppressed from moving away from each other.

The second member may further comprise a second holding portion disposed at a side of the second contacting portion opposite from the second opposing portion. The second contacting portion may be interposed between the second opposing portion and the second holding portion. According to this configuration, the fastener is held by being interposed between the second opposing portion and the second holding portion of the second member in addition to being interposed between the first opposing portion and the first holding portion of the first member. Due to this, the first member, the second member, and the fastener may be firmly fixed.

The fastener and at least one member, which is the first member and/or the second member, engage with each other to restrict the fastener from moving in a direction perpendicular to a direction in which the first member and the second member are arranged. According to this configuration, the fastener may be suppressed from moving relative to the first member and the second member. Due to this, a force may be suppressed from being applied on welded portions of the fastener with each of the first member and the second member in the direction perpendicular to the direction in which the first member and the second member are arranged, and thus the welded portion can be suppressed from coming off.

The present disclosure discloses an electric pump comprising an upper housing, a lower housing, and a flange fastening the upper housing and the lower housing to each other. The flange may comprise: a fastening being fastened to each of the upper housing and the lower housing by injection welding; and an assembly mechanism that is integrally formed with the fastening portion, and has a fastening hole. A fastener member to be fastened to an external device may be inserted through the fastening hole.

According to this configuration, the upper housing and the lower housing may be fastened by the flange. That is, the flange may comprise a structure for fastening the upper housing and the lower housing, as well as a structure for assembling the electric pump to the external device. Due to this, it is not necessary to provide an assembly mechanism separately and then dispose the assembly mechanism in the electric pump.

First Embodiment Configuration of Electric Pump 10

An electric pump 10 is to be provided in an engine room of a vehicle such as an automobile, and is used for circulating cooling water to cool down an engine or an inverter. As shown in FIG. 1, the electric pump 10 comprises a housing 12, a pump unit 20, motor unit 40, and a flange 100. The housing 12 accommodates the pump unit 20 and motor unit 40. The housing 12 comprises an upper housing 28 and a lower housing 46. The upper housing 28 and the lower housing 46 are constituted of a same kind of resin material. It should be noted that each term indicating a direction such as “upper” and “lower” in the embodiments is merely used for explanation, and is not intended to define an actual direction in which the electric pump 10 is mounted on the vehicle.

The upper housing 28 comprises an inlet 22 and an outlet 23. The pump unit 20 is disposed on the upper housing 28. The pump unit 20 comprises so impeller 26.

The motor unit 40 disposed below the pump unit 20. The motor unit 40 is disposed across the lower housing 46 and the upper housing 28. The motor unit 40 is a three-phase brushless motor. The motor unit 40 comprises a shaft 16, a rotor 60, a stator 44 and a control circuit 18.

The stator 44 comprises a core 43, coils 42, and a motor housing 45 constituted of resin. The motor housing 45 covers the core 43 and the coils 42. The motor housing 45 is constituted of a resin material of a same kind as that of the upper housing 28 and the lower housing 46. FIG. 1 shows cross-sections of the core 43 and the coils 42, but omits hatchings that represent the cross-sections for easier view. The stator 44 is electrically connected to the control circuit 18. The control circuit 18 is configured to control power supply to the stator 44. The control circuit 18 is connected to an external power source not shown (e.g., a battery mounted on a vehicle) via a terminal 14. The control circuit 18 supplies power from the external power source to the stator 44.

The shaft 16 extends vertically inside the housing 12, and an upper end of the shaft 16 reaches the pump unit 20. A lower end of the shaft 16 is fixed to the motor housing 45. A rotor 60 is rotatably attached to the shaft 16. The rotor 60 comprises a plurality of magnets 66 which opposes the stator 44.

The upper housing 28, the motor housing 45, and the lower housing 46 are disposed so as to overlap each other at their outer peripheral edges. Specifically, the upper housing 28 comprises an opposing portion 28 a which surrounds the outer peripheral edge of the upper housing 28. The opposing portion 28 a has a circular shape protruding outward from the upper housing 28. The lower housing 46 comprises an opposing portion 46 a which surrounds the outer peripheral edge of the lower housing 46. The opposing portion 46 a has a circular shape protracting outward from the lower housing 46. The opposing portion 46 a opposes the opposing portion 28 a over its entire length.

An opposing portion 45 a of the motor housing 45 is disposed between the opposing portion 28 a and the opposing portion 46 a. The opposing portion 45 a surrounds the outer peripheral edge of the motor housing 45. The opposing portion 45 a has a circular shape protruding outward from the motor housing 45. The opposing portion 45 a is interposed between the opposing portion 28 a and the opposing portion 46 a. The opposing portion 45 a is in contact with the opposing portion 28 a and the opposing portion 46 a over its entire length.

The flange 100 is fixed to the opposing portions 28 a, 45 a, and 46 a. The flange 100 comprises assembly mechanisms 101, a fastening portion 103, and contacting portions 104, 106. The fastening portion 103 is disposed outside outer peripheral surfaces 28 b, 45 b and 46 b of the opposing portions 28 a, 45 a and 46 a, and is fixed to each of the outer peripheral surfaces 28 b, 45 b and 46 b by injection welding. Due to this, the upper housing 28, the lower housing 46, and the motor housing 45 are fixed to each other. As shown in FIG. 2, the listening portion 103 has a circular shape that surrounds the outer peripheral edges of the opposing portions 28 a, 45 a, and 46 a.

A contacting portion 104 is disposed at an upper end of the fastening portion 103. The contacting portion 104 has a circular shape. The contacting portion 104 is in contact with an upper face of the opposing portion 28 a at a side opposite from the opposing portions 45 a and 46 a over an entire length of the opposing portion 28 a. Due to this, the upper housing 28 can be prevented from moving away from the motor housing 45 and the lower housing 46. An inner peripheral edge of the contacting portion 104 is in contact with a lateral side surface of the upper housing 28.

A contacting portion 106 is disposed at a lower end of the fastening portion 103. The contacting portion 106 has a circular shape. The contacting portion 106 is in contact with a lower surface of the opposing portion 46 a at a side opposite from the opposing portions 28 a and 45 a over an entire length of the opposing portion 46 a. Due to this, the lower housing 46 can be prevented from moving away from the motor housing 45 and the upper housing 28. Further, by the contacting portions 104, 106 interposing the opposing portions 28 a, 45 a, and 46 a from above and below, the upper housing 28, the motor housing 45, and the lower housing 46 can be fixed firmly. An inner peripheral edge of the contacting portion 106 is in contact with a lateral side surface of the lower housing 46.

A pair of assembly mechanisms 101 is disposed outside the fastening portion 103. Each of the assembly mechanisms 101 has a flat plate shape extending outward from the fastening portion 103. A fastening hole 102 is disposed at an intermediate position of each of the assembly mechanisms 101. Each of the fastening holes 102 penetrates the corresponding assembly mechanism 101. As shown to FIG. 1, the electric pump 10 is fixed to a vehicle body X when each bolt B which is inserted through the corresponding fastening hole 102 is fastened to the vehicle body X.

Next, a method of forming the flange 100 will be described. As shown in FIG. 3, in the forming method, firstly in S12, the pump unit 20 and the motor unit 40 are housed, and the upper housing 28, the motor housing 45, and the lower housing 46 are assembled to produce the housing 12. Next, in S14, laser is irradiated to the outer peripheral surfaces 28 b, 45 b and 46 b of the opposing portions 28 a, 45 a, 46 a to process these surfaces. Due to this, the flange 100 can be easily welded by injection molding in a later step.

Further, since the outer peripheral surfaces 28 b, 45 b and 46 b of the opposing portions 28 a, 45 a, 46 a have a circular shape, it is not necessary to adjust a distance between laser and the housing 12 over entire lengths of the outer peripheral surfaces 28 b, 45 b and 46 b during the laser processing.

Next, in S16, the housing 12 is placed in a die. Next, in S18, injection molding is performed and the flange 100 is formed. At this occasion, molten material which is to be formed into the flange 100 makes contact with the outer peripheral surfaces 28 b, 45 b and 46 b. When the molten material is solidified and the flange is formed, the flange 100 is injection welded to the outer peripheral surfaces 28 b, 45 b and 46 b. According to this forming method, the fastening portion 103 and the assembly mechanisms 101 can also be integrally formed by a single molding. Further, the contacting portions 104, 106 can be integrally formed with the fastening portion 103 and the assembly mechanisms 101 by the single molding.

Next, in S20, the flange 100 is taken out of the die is a state of being injection welded to the housing 12, and forming of the flange 100 is thereby completed.

In the flange 100, the fastening portion 103 which fastens the upper housing 28, the motor housing 45 and the lower housing 46 to each other, and the assembly mechanisms 101 having fastening holes 102 for attaching the upper housing 28, the motor housing 45, and the lower housing 46 to the vehicle body X, can be integrally formed. Due to this, it is not necessary to dispose the fastening portion 103 and the assembly mechanisms 101 separately. Due to this an operation for assembling the electric pump 10 to the vehicle body X can be simplified.

Second Embodiment

Differences from the first embodiment will be described. Same signs will be given to same configurations as those in the first embodiment, and explanations thereof will be omitted. As shown in FIG. 4, the present embodiment, a housing 212 has a different shape from a shape of the housing 12 of the first embodiment. Specifically, an upper housing 228 and a lower housing 246 have different shapes from the shapes of the upper housing 28 and the lower housing 46 of the first embodiment, respectively. The upper housing 228 comprises a holding portion 228 c which is in contact with the contacting portion 104 of the flange 100. The holding portion 228 c has a circular shape. The holding portion 228 c is in contact with an upper surface of the contacting portion 104 over an entire length of the contacting portion 104. The contacting portion 104 is held by being interposed between the holding portion 228 c and the opposing portion 28 a. The other configurations of the upper housing 228 are the same as those of the upper housing 28.

The lower housing 246 comprises a holding portion 246 c which is in contact with the contacting portion 106 of the flange 100. The holding portion 246 c has a circular shape. The holding portion 246 c is in contact with a lower surface of the contacting portion 106 over an entire length of the contacting potion 106. The contacting portion 106 is held by being interposed between the holding portion 246 c and the opposing portion 46 a. The other configurations of the lower housing 246 are the same as those of the lower housing 46.

According to this configuration, the flange 100 can be firmly fixed to the housing 12.

Third Embodiment

Differences from the first embodiment will be described. Same signs will be given to same configurations as those of the first embodiment, and explanations thereof will be omitted. As shown in FIG. 5, in the present embodiment, a housing 312 has a different shape from a shape of the housing 12 of the first embodiment. Specifically, an upper housing 328 and a lower housing 346 have different shapes from the shapes of the upper housing 28 and the lower housing 46 of the first embodiment, respectively. Further, in the present embodiment, a motor housing 345 has a different shape from the shape of the motor housing 45 of the first embodiment. Further, in the present embodiment, a flange 300 has a different shape from the shape of the flange 100.

The upper housing 328 comprises an opposing portion 328 a. The opposing portion 328 a has a circular shape protruding outward from the upper housing 328. A thickness of the outer peripheral edge of the upper housing 328 is greater than a thickness of the other portion of the upper housing 328. The outer peripheral edge of the upper housing 328 protrudes downward more than the other portion of the upper housing 328. The other configurations of the upper housing 328 are the same as configurations of the upper housing 28.

The lower housing 346 comprises an opposing portion 346 a. The opposing portion 346 a has a circular shape protruding outward from the lower housing 346. The opposing portion 346 a is disposed below the opposing portion 328 a with an intervenient space therebetween. The opposing portion 346 a and the opposing portions 328 a are opposed to each other at an interval. A thickness of the outer peripheral edge of the lower housing 346 is greater than a thickness of the other portion of the lower housing 346. The outer peripheral edge of the lower housing 346 protrudes upward, that is, toward an upper housing 328 side more than the other portion of lower housing 346. The other configurations of the lower housing 346 are the same as configurations of the lower housing 46.

The motor housing 345 does not include an opposing portion positioned between the opposing portion 328 a and the opposing portion 346 a. The other configurations of the motor housing 345 are the same as those of the motor housing 45.

The flange 300 comprises a pair of assembly mechanisms 301 and a fastening portion 303. In the flange 300, the pair of assembly mechanisms 301 and the fastening portion 303 are integrally formed. Each of the assembly mechanisms 301 has a same configuration as the configuration of each assembly mechanism 101 of the flange 100, and has a fastening hole 302 which is similar to each fastening hole 102. The fastening portion 303 is positioned in a gap between the opposing portion 328 a and the opposing portion 346 a. The fastening portion 303 is injection welded to each of a lower surface 328 b of the opposing portion 328 a, a lateral side surface 328 c of the upper housing 328, an upper surface 346 b of the opposing portion 346 a, and a lateral side surface 345 a of the motor horsing 345.

The lower surface 328 b, the lateral side surface 328 c, the upper surface 346 b, and the side lateral surface 345 a are surface-processed by laser irradiation. The laser irradiation is performed on the upper housing 328, the motor housing 345, and the lower housing 346 separately.

According to this configuration as well, in the flange 300, the fastening portion 303 and the assembly mechanisms 301 are integrally formed, and thus it is not necessary to dispose the fastening portion 303 and the assembly mechanisms 301 separately.

Fourth Embodiment

Differences from the first embodiment will be described. Same signs will be given to same configurations as those of the first embodiment, and explanations thereof will be omitted. As shows in FIG. 6, in the present embodiment, an assembly mechanism 401 of a flange 400 has a different shape from the shape of each assembly mechanism 101 of the flange 100.

The flange 400 comprises the fastening portion 103, the contacting portions 104, 106 which are same as those of the flange 100, besides the assembly mechanism 401. The assembly mechanism 401 is disposed at an outer peripheral edge of the fastening portion 103. The assembly mechanism 401 has a flat plate shape parallel to a vertical direction. The assembly mechanism 401 is integrally formed with the fastening portion 103, and contacting portions 104, 106. The assembly mechanism 401 has a fastening bole 402 which penetrates the assembly mechanism 401.

According to this configuration as well, in the flange 400, the fastening portion 103 and the assembly mechanism 401 are integrally formed, and thus it is not necessary to dispose the fastening portion 103 and the assembly mechanism 401 separately.

Fifth Embodiment

Differences from the first embodiment will be described. Same signs will be given to same configurations as those of the first embodiment, and explanations thereof will be omitted. As shown in FIG. 7, in the present embodiment, a fastening portion 503 of a flange 500 has a different shape from the shape of the fastening portion 103 of the flange 100. Further, in the present embodiment, an opposing portion 528 a of an upper housing 528 has a different shape from the shape of the opposing portion 28 a of the upper housing 28. The other shapes of the flange 500 are same as the shapes of the flange 100. Further, the other shapes of the upper housing 528 are the same as the shapes of the upper housing 28.

An opposing portion 528 a comprises a flat plate 528 c disposed at a portion of its outer peripheral surface 528 b. The fastening portion 503 comprises a flat plate 503 a which is in contact with the flat plate 528 c. The flat plate 528 c and the flat plate 503 a are in contact with each other over an entirety of their surfaces. Moreover, the fastening portion 503 is also in contact with an entirety of the outer peripheral surface 528 b other than the flat plate 528 c.

According to this configuration, the flange 500 can be restrained from moving in a direction perpendicular to the vertical direction by the fastening portion 503 and the opposing portion 528 a engaging each other. Due to this, a load exerted on welded portions of the fastening portion 503 with the opposing portions 528 a, 45 a and 46 a can be induced. Due to this, the welded portions can be suppressed from coming off.

In a variant, at least one of the opposing portion 46 a of the lower housing 46 and the opposing portion 45 a of the motor housing 45 may include a flat plate portion like the flat plate 528 c. At this occasion, the fastening portion 503 may have a flat plate which makes contact with the flat plate portion.

Variants Variant 1

In each of the above embodiments, the lower housing 46 has a cylindrical shape below the opposing portion 46 a. However, for example as shown in FIG. 8, the lower housing 46 may comprise a protrusion 46 x below the opposing portion 46 a at a position where the lower housing 46 contacts the contacting portion 106. In this case, the contacting portion 106 may comprise a recess 106 x that receives the protrusion 46 x at a position where the contacting portion 106 contacts the protrusion 46 x. According to this configuration, the flange 100 can be restrained from moving in a direction perpendicular to the vertical direction by the protrusion 46 x and the recess 106 x engaging each other. Due to this, a load exerted on welded portions of the fastening portion 103 with the opposing portions 28 a, 45 a and 46 a can be reduced. Due to this, the welded portions can be suppressed from coming off.

A protrusion may be disposed on the upper housing 28 additionally or alternatively on the lower housing 46. Further, shapes by which the flange 100 and the housing 12 are engaged with each other are not limited to combination of a protrusion and a recess. For example, similarly to the fifth embodiment, the flange 100 and at least one of the lower housing 46 and the upper housing 28 may comprise first plate shapes which overlap each other. Alternatively, the flange 100 and at least one of the lower housing 46 and the upper housing 28 may comprise corner portions which overlap each other. Generally, the flange 100 and at least one of the upper housing 28 and the lower housing 46 may be formed into any shape as long as the flange 100 is engaged with the housing 12 and is restricted from rotating and moving in a circumferential direction with respect to the housing 12. The same applies to the second embodiment to the fifth embodiment. Further, shapes used for these engagements may be provided at a plurality of positions. According to this configuration, the shape for engagement may be provided at a position different from surfaces to be processed by laser irradiation. Due to this, it is not necessary to provide the shape for engagement at the surfaces to be processed by laser irradiation.

Variant 2

In the fifth embodiment, portions of the flange 500 and the opposing portions 528 a, 45 a, 46 a, where the flange 500 engages with the opposing portions 528 a, 45 a, 46 a, may not be formed into flat plate shapes. For example, similarly to the above variant 1, at least one of the flange 500 and the opposing portions 528 a, 45 a, 46 a may comprise a protrusion, and the other may comprise a recess that receives the protrusion at a position corresponding to the protrusion. Alternatively, for example, the flange 500 and at least one of the opposing portions 528 a, 45 a, 46 a may comprise corner portions which overlap each other. Generally, the flange 500 and at least one of the opposing portions 528 a, 45 a, 46 a may be formed into any shape as long as the flange 500 is engaged with at least one of the housings 528, 45, 46 and is restricted from rotating and moving in a circumferential direction with respect to the at least one of the housings. The same applies to the second embodiment to the fourth embodiment. Further, shapes used for these engagements may be provided at a plurality of positions.

Variants 3

The “electric pump” in the present disclosure may be used for fluids other than cooling water such as fuel and drinking water. Further, the “electric pump” in the present disclosure may comprise, for example, a motor with a brush instead of the brushless motor.

Variant 4

The “device with an assembly mechanism” in the present disclosure may be a device other than the electric pump. For example, as shown in FIG 9, the device with the assembly mechanism may be a case 900 that comprises a first member 902, a second member 904, and a fastener 906. The fastener 906 may comprise a fastening portion 906 a which is fastened to each of a surface 902 a of the first member 902 and a surface 904 a of the second member 904 by injection welding. Further, the fastener 906 may comprise an assembly mechanism 908 which is inserted through a fastening hole or the like of an external device and fixed to the external device. 

1. A device with an assembly mechanism, comprising: a first member; a second member; and a fastener fastening the first member and the second member to each other, wherein the fastener comprises; a fastening portion being fastened to each of the first member and second member by injection welding; and the assembly mechanism that is integrally formed with the fastening portion, and is configured to assemble the device to an external device.
 2. The device with the assembly mechanism as in claim 1, wherein the first member comprises a first opposing portion, the second member comprises a second opposing portion opposing the first opposing portion, and the fastener further comprises a first contacting portion contacting the first opposing portion at a side of the first opposing portion opposite from the second opposing portion.
 3. The device with the assembly mechanism as in claim 2, wherein the first member further comprises a first holding portion disposed at a side of the first contacting portion opposite from the first opposing portion, and the first contacting portion is interposed between the first opposing portion and the first holding portion.
 4. The device with the assembly mechanism as in claim 2, wherein the fastener further comprises a second contacting portion contacting the second opposing portion at a side of the second opposing portion opposite from the first opposing portion.
 5. The device with the assembly mechanism as in claim 4, wherein the second member further comprises a second holding portion disposed at a side of the second contacting portion opposite from the second opposing portion, and the second contacting portion is interposed between the second opposing portion and the second holding portion.
 6. The device with the assembly mechanism as in claim 1, wherein the fastener and at least one of the first member and the second member engage with each other to restrict the fastener from moving in a direction perpendicular to a direction in which the first member and the second member are arranged.
 7. An electric pump comprising: an upper housing; a lower housing; a flange fastening the upper housing and the lower housing to each other, wherein the flange comprises: a fastening portion being fastened to each of the upper housing and the lower housing by injection welding; and an assembly mechanism that is integrally formed with the fastening portion, the assembly mechanism including a fastening hole, and a fastener member to be fastened to an external device is inserted through the fastening hole. 